Original English Title: dendrimer Au nanoparticle network covered alumina membrane for ion correction and enhanced Bioanalysis
Corresponding authors: Wang Chen (China Pharmaceutical University); Xia Xinghua (Nanjing University); Li Ju (MIT)
Authors: Chen Wang, Xiao Ping Zhao, Fei Fei Liu, Yuming Chen, Xing Hua Xia, Ju Li
Nano channel devices have nano porous structure and easy to modify the surface / interface, which show great application prospects in DNA sequencing, single molecule sensing, energy storage and conversion, voltage-gated ion channels and so on. When the pore structure, surface charge distribution and bulk electrolyte concentration of the nanochannel are asymmetric, a unidirectional ion transport characteristic similar to that of the diode will be generated, which is called ionic current rectification (ICR). The key factors affecting the rectifying properties of ion current are the asymmetry of surface charge distribution and channel structure. Therefore, the in-situ real-time dynamic monitoring of biomolecular recognition can be realized by using the changes of ICR properties of nano devices before and after biomolecular recognition, while the sensitivity and specificity of analysis and detection mainly depend on the ICR properties and surface properties of rectifier devices.
Recently, Dr. Wang Chen from China Pharmaceutical University, Professor Xia Xinghua from Nanjing University, and Professor Li Ju from Massachusetts Institute of technology worked together to design and prepare a gold nano network / alumina composite ion rectifier. Through chemical coupling technology, the rectifier device in-situ grows and arranges the polymer and gold nanoparticles on the surface of alumina array nano channel film (Fig. 1), so that it has significant asymmetry in geometric structure and surface charge distribution, so it has good ion rectification properties (Fig. 2). In the study, the author first studied the ion selectivity of the device. Whether the small molecule probe with different charge can pass through the composite device under the electric field driving is verified that the ion rectifier device has the function of anion selective transmission. Then, the influence of different concentration of gold nanoparticles, thickness and channel size of alumina film, pH value of the system, concentration and valence of electrodialysis on the ICR properties of the composite device is discussed, and the ion integrity of the composite device is described in detail The mechanism of flow generation and regulation.
Figure 1. Preparation and characterization of gold nanonetwork / alumina composite ion rectifying device
Figure 2. Study on material transport properties and mechanism of gold nanonetwork / alumina composite ion rectifying device
On the basis of the above research, the rectifier is used in the highly sensitive recognition, capture and detection of circulating tumor cells (Fig. 3). Firstly, the aptamer probe which can specifically identify the target cell was modified and fixed on the gold nano network structure, and the biological sample was transported and precisely located by the fluid control performance of the nanofluidic system; the target cell was specifically captured based on the molecular recognition principle; the significant changes of ICR properties of the composite device before and after cell capture were used to achieve the target cell's Finally, in the presence of lysozyme, the captured cells can be released with high activity for further downstream research.
Figure 3. High sensitive capture, detection and release of circulating tumor cells by gold nanonetwork / alumina composite ion rectifying device
The composite ion rectifying device not only has excellent ion current rectifying property, but also can utilize the high specific surface area, good biocompatibility and Au-S functional group which is easy to be fixed and modified on the surface of gold nano network structure to realize the high sensitive recognition and capture of biomolecule / cell and in-situ dynamic analysis. The research results provide a new idea for the application of nanoflow control system in high sensitive bioanalysis.
This achievement was recently published on nano letters, with Dr. Wang Chen of China Pharmaceutical University as the first / corresponding author, and Professor Xia Xinghua of Nanjing University and Professor Li Ju of Massachusetts Institute of technology as the corresponding author.
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Dendrimer-Au Nanoparticle Network Covered Alumina Membrane for Ion Rectification and Enhanced Bioanalysis
Chen Wang, Xiao-Ping Zhao, Fei-Fei Liu, Yuming Chen, Xing-Hua Xia, Ju LiNano Lett., 2020, DOI: 10.1021/acs.nanolett.9b05066Publication Date: Feb. 24, 2020Copyright ? 2020 American Chemical Society
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